Signal lights of the type used on emergency vehicles such as police cars, fire trucks, ambulances, and wreckers, have progressed from simple dome lights to elaborate light bars which include a variety of types of signaling and special purpose lights. These light bars are capable of producing a variety of light signals in various colors and patterns, each such signal having a particular purpose or significance. These light bars include many varieties of stationary, rotating, and oscillating lights.
A particular problem with existing light bars has been protecting the various light devices from the elements. Water, dirt, and road salt leaking into the light bar can damage the components. Another problem with these light bars has been the extreme heat generated by the lights, which is difficult to dissipate from a sealed light bar. The high temperatures reached inside the light bar can damage the electronic circuitry controlling the various lights. Still another problem has been providing sufficient flexibility in signal light patterns in a single light bar to meet the needs of the emergency vehicle and remain in compliance with federal, state, and local regulations on light signals. These regulations control, for example, the colors of light that can be used in particular situations. Thus it is important that the colors of the lights in the light bar are isolated.